leaderboard

Leaderboards backed by Redis in Ruby.

Builds off ideas proposed in http://www.agoragames.com/blog/2011/01/01/creating-high-score-tables-leaderboards-using-redis/.

Installation

gem install leaderboard

or in your Gemfile

gem 'leaderboard'

Make sure your redis server is running! Redis configuration is outside the scope of this README, but check out the Redis documentation.

Compatibility

The gem has been built and tested under 2.2.1.

NOTE: The gem should work fine in earlier versions of Ruby such as 1.8.7 or 1.9.3. There are no specific aspects of Ruby 2.x that we utilize at this time.

Usage

Creating a leaderboard

Be sure to require the leaderboard library:

require 'leaderboard'

Create a new leaderboard or attach to an existing leaderboard named 'highscores':

  highscore_lb = Leaderboard.new('highscores')
   => #<Leaderboard:0x0000010307b530 @leaderboard_name="highscores", @page_size=25, @redis_connection=#<Redis client v2.2.2 connected to redis://localhost:6379/0 (Redis v2.2.5)>>

Defining leaderboard options

The Leaderboard::DEFAULT_OPTIONS are as follows:

DEFAULT_OPTIONS = {
  :page_size => DEFAULT_PAGE_SIZE,
  :reverse => false,
  :member_key => :member,
  :rank_key => :rank,
  :score_key => :score,
  :member_data_key => :member_data,
  :member_data_namespace => 'member_data',
  :global_member_data => false
}

The DEFAULT_PAGE_SIZE is 25.

You would use the option, :reverse => true, if you wanted a leaderboard sorted from lowest-to-highest score. You may also set the reverse option on a leaderboard after you have created a new instance of a leaderboard. The various ..._key options above control what data is returned in the hash of leaderboard data from calls such as leaders or around_me. Finally, the global_member_data option allows you to control whether optional member data is per-leaderboard (false) or global (true).

If you need to pass in options for Redis, you can do this in the initializer:

  redis_options = {:host => 'localhost', :port => 6379, :db => 1}
   => {:host=>"localhost", :port=>6379, :db=>1}
  highscore_lb = Leaderboard.new('highscores', Leaderboard::DEFAULT_OPTIONS, redis_options)
   => #<Leaderboard:0x00000103095200 @leaderboard_name="highscores", @page_size=25, @redis_connection=#<Redis client v2.2.2 connected to redis://localhost:6379/1 (Redis v2.2.5)>>

You can pass in an existing connection to Redis using :redis_connection in the redis_options hash:

  redis = Redis.new
   => #<Redis client v2.2.2 connected to redis://127.0.0.1:6379/0 (Redis v2.2.5)>
  redis_options = {:redis_connection => redis}
   => {:redis_connection=>#<Redis client v2.2.2 connected to redis://127.0.0.1:6379/0 (Redis v2.2.5)>}
  highscore_lb = Leaderboard.new('highscores', Leaderboard::DEFAULT_OPTIONS, redis_options)
   => #<Leaderboard:0x000001028791e8 @leaderboard_name="highscores", @page_size=25, @redis_connection=#<Redis client v2.2.2 connected to redis://127.0.0.1:6379/0 (Redis v2.2.5)>>

To use the same connection for multiple leaderboards, reset the options hash before instantiating more leaderboards:

redis = Redis.new
 => #<Redis client v2.2.2 connected to redis://127.0.0.1:6379/0 (Redis v2.2.5)>
redis_options = {:redis_connection => redis}
 => {:redis_connection=>#<Redis client v2.2.2 connected to redis://127.0.0.1:6379/0 (Redis v2.2.5)>}
highscore_lb = Leaderboard.new('highscores', Leaderboard::DEFAULT_OPTIONS, redis_options)
redis_options = {:redis_connection => redis}
other_highscore_lb = Leaderboard.new('other_highscores', Leaderboard::DEFAULT_OPTIONS, redis_options)

You can set the page size to something other than the default page size (25):

  highscore_lb.page_size = 5
   => 5
  highscore_lb
   => #<Leaderboard:0x000001028791e8 @leaderboard_name="highscores", @page_size=5, @redis_connection=#<Redis client v2.2.2 connected to redis://127.0.0.1:6379/0 (Redis v2.2.5)>>

Ranking members in the leaderboard

Add members to your leaderboard using rank_member:

  1.upto(10) do |index|
    highscore_lb.rank_member("member_#{index}", index)
  end
   => 1

You can call rank_member with the same member and the leaderboard will be updated automatically.

Get some information about your leaderboard:

  highscore_lb.total_members
   => 10
  highscore_lb.total_pages
   => 1

The rank_member call will also accept an optional parameter, member_data that could be used to store other information about a given member in the leaderboard. This may be useful in situations where you are storing member IDs in the leaderboard and you want to be able to store a member name for display. You could use JSON to encode a Hash of member data. Example:

require 'json'
highscore_lb.rank_member('84849292', 1, {'username' => 'member_name'}.to_json)

You can retrieve, update and remove the optional member data using the member_data_for, update_member_data and remove_member_data calls. Example:

JSON.parse(highscore_lb.member_data_for('84849292'))
 => {"username"=>"member_name"}

highscore_lb.update_member_data('84849292', {'last_updated' => Time.now, 'username' => 'updated_member_name'}.to_json)
 => "OK"
JSON.parse(highscore_lb.member_data_for('84849292'))
 => {"username"=>"updated_member_name", "last_updated"=>"2012-06-09 09:11:06 -0400"}

highscore_lb.remove_member_data('84849292')

If you delete the leaderboard, ALL of the member data is deleted as well.

Optional member data notes

If you use optional member data, the use of the remove_members_in_score_range or remove_members_outside_rank methods will leave data around in the member data hash. This is because the internal Redis method, zremrangebyscore, only returns the number of items removed. It does not return the members that it removed.

Get some information about a specific member(s) in the leaderboard:

  highscore_lb.score_for('member_4')
   => 4.0
  highscore_lb.rank_for('member_4')
   => 7
  highscore_lb.rank_for('member_10')
   => 1

Retrieving members from the leaderboard

Get page 1 in the leaderboard:

  highscore_lb.leaders(1)
   => [{:member=>"member_10", :rank=>1, :score=>10.0}, {:member=>"member_9", :rank=>2, :score=>9.0}, {:member=>"member_8", :rank=>3, :score=>8.0}, {:member=>"member_7", :rank=>4, :score=>7.0}, {:member=>"member_6", :rank=>5, :score=>6.0}, {:member=>"member_5", :rank=>6, :score=>5.0}, {:member=>"member_4", :rank=>7, :score=>4.0}, {:member=>"member_3", :rank=>8, :score=>3.0}, {:member=>"member_2", :rank=>9, :score=>2.0}, {:member=>"member_1", :rank=>10, :score=>1.0}]

You can pass various options to the calls leaders, all_leaders, around_me, members_from_score_range, members_from_rank_range and ranked_in_list. Valid options are:

• :with_member_data - true or false (default) to return the optional member data.
• :page_size - An integer value to change the page size for that call.
• :members_only - true or false (default) to return only the members without their score and rank.
• :sort_by - Valid values for :sort_by are :none (default), :score and :rank.
• :include_missing - true (default) or false to return members that are not ranked.

You can also use the members and members_in methods as aliases for the leaders and leaders_in methods.

There are also a few convenience methods to be able to retrieve all leaders from a given leaderboard. They are all_leaders and all_leaders_from. You may also use the aliases all_members or all_members_from. Use any of these methods sparingly as all the information in the leaderboard will be returned.

Add more members to your leaderboard:

  50.upto(95) do |index|
    highscore_lb.rank_member("member_#{index}", index)
  end
   => 50
  highscore_lb.total_pages
   => 3

Get an "Around Me" leaderboard page for a given member, which pulls members above and below the given member:

  highscore_lb.around_me('member_53')
   => [{:member=>"member_65", :rank=>31, :score=>65.0}, {:member=>"member_64", :rank=>32, :score=>64.0}, {:member=>"member_63", :rank=>33, :score=>63.0}, {:member=>"member_62", :rank=>34, :score=>62.0}, {:member=>"member_61", :rank=>35, :score=>61.0}, {:member=>"member_60", :rank=>36, :score=>60.0}, {:member=>"member_59", :rank=>37, :score=>59.0}, {:member=>"member_58", :rank=>38, :score=>58.0}, {:member=>"member_57", :rank=>39, :score=>57.0}, {:member=>"member_56", :rank=>40, :score=>56.0}, {:member=>"member_55", :rank=>41, :score=>55.0}, {:member=>"member_54", :rank=>42, :score=>54.0}, {:member=>"member_53", :rank=>43, :score=>53.0}, {:member=>"member_52", :rank=>44, :score=>52.0}, {:member=>"member_51", :rank=>45, :score=>51.0}, {:member=>"member_50", :rank=>46, :score=>50.0}, {:member=>"member_10", :rank=>47, :score=>10.0}, {:member=>"member_9", :rank=>48, :score=>9.0}, {:member=>"member_8", :rank=>49, :score=>8.0}, {:member=>"member_7", :rank=>50, :score=>7.0}, {:member=>"member_6", :rank=>51, :score=>6.0}, {:member=>"member_5", :rank=>52, :score=>5.0}, {:member=>"member_4", :rank=>53, :score=>4.0}, {:member=>"member_3", :rank=>54, :score=>3.0}, {:member=>"member_2", :rank=>55, :score=>2.0}]

Get rank and score for an arbitrary list of members (e.g. friends) from the leaderboard:

  highscore_lb.ranked_in_list(['member_1', 'member_62', 'member_67'])
   => [{:member=>"member_1", :rank=>56, :score=>1.0}, {:member=>"member_62", :rank=>34, :score=>62.0}, {:member=>"member_67", :rank=>29, :score=>67.0}]

Retrieve members from the leaderboard in a given score range:

members = highscore_lb.members_from_score_range(4, 19)
 => [{:member=>"member_10", :rank=>47,